Lockout for party-lines or extension-telephones.



, 0. D. M. GUTHE.

LOCKOUT FOR PARTY LINES 0R EXTENSION TELEPHONES.

APPLICATION FILED MAY 13. 1915.

1,1 99,783. Patented Oct. 3, 1916.

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TES ATN OLOF DAVID MATTHIAS GUTHE, OF EAST ORANGE, NEW JERSEY, ASSIGNOR, BY MESNE ASSIGNMENTS, '10 WESTERN ELECTRIC COMPANY, INCORPORATED, A

CORPORATION OF NEW YORK.

weaves.

Specification of Letters Patent.

Patented Oot.3,-1916.

Application filed May 13, 1915. Serial No. 27,782.

To all whom it may concern:

Be it known that I, OLOF DAVID MATTHIAS GUTHE, a citizen of the United States, residing at East Orange, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Lockouts for Party-Lines .or Extension-Telephones, of which the following is a full, clear, concise, and exact description.

This invention relates to a lookout for party line or extension telephones on a twowire line system. Its object is to give a party, when he removes his receiver in using a line, a clear circuit to the central oflice, free from interruptions by any other party on the same line.

This invention is of particular importance as embodied in an automatic telephone system, since it prevents interference between the subscribers on party lines during the time of selection.

In accordance with this invention each station is provided with a relay for discontinuing the extension of one or both line conductors beyond that station, the arrangement of the stations being such that one of the two exchange line conductors is carried. first to one of the stations extending through contacts controlled by the relay at that station to the next station in order, and similarly extended consecutively to each of the other stations of the party line group. The other of the two line conductors is similarly extended to each of the stations, but in the reverse order. With this arrangement it is possible, by operating the relay at a given station, to prevent the stations on either side of that station from gaining access to the line.

This invention is illustrated in the accompanyin g drawing in which Figure 1 shows it as applied to an automatic telephone system, and Fig. 2 as applied to a manual system.

In the drawing four subscribers stations, A, B, C and D, are shown arranged for connection with a pair of exchange line conductors 1 and 2. Line conductor 1 is extended first to relay 3 associated with station A, thence through station A to contact 16 of relay 4 associated with station B, thence to contact 11 of relay 5 associated with station C, thence through contact 12 either anautomatic or a manual telephone system. The connections of an automatlc system are indicated in the right-hand portion of Fig. 1, the line finder being inclicated at 13 and the usual line and cut-off relays 14 and 15 provided. The contact spring 16 of relay 14 controls the closure of the circuit of the starter wire 17. The connections of a manual system are indicated in Fig. 2 by means of the usual equipment consisting of a jack 18 and cooperating plug 19, the line and cut-off relays 14 and 15 and line lamp 20.

The operation of the particular embodiment of this invention shown in the drawing is as follows: Let it be assumed that one of the subscribers, for example a subscriber at station B, wishes to initiate a call. He removes the receiver from its hook, thereby closing a circuit as follows: From batteryv 21, at the central oflice, through right-hand winding of relay 14, contact 22, line wire 1, contact 7 of relay 3, relay 4, conductor 23, subscribers telephone set, conductor 24, contacts 11 and 12 of relays 5 and 6 respectively, linewire 2, contact 25,

left-hand winding of relay 14, to ground.

Relay 4 is thereby energized, which in pulling up its armatures opens contacts 8 and 10, thus cutting off the other stations A, C and D, and hence none of said subscribers can interfere with the use of the common line by the subscriber whose line is already cut in.

The relays 3, 4, 5 and 6 are shown as inserted in a transmission circuit, but since said relays are of the slow release type and may employ a short-circuited secondary winding in the form of a copper tube, the transmission loss is inconsiderable. Due to the fact that these relays are of the type slow in releasing, in event this invention is used in connection with an automatic system during the time the line circuit is interrupted by the sending of impulses from any given station, the respective relay of that station will remain in an operated posiat any station causing the operation of the tion, thereby preventing the possibility of interference from any of the other stations during the sending of impulses.

It will be apparent from the above that with the relays 3, 4, 5 and 6 located at the respective substations A, B, G and D, three conductors will be necessary for interconnecting the various substations, but if said relays are located at some central point (as indicated by dotted lines) and suitably protected, one of these conductors may be eliminated.

7 What is claimed is:

1, In a telephone system, line conductors connecting a plurality of subscribers stations, telephonic apparatus at each station, and a relay individual to each station, the operation of the relay at any station, telephonically isolating the apparatus atall other" stations from the line conductors.

2. In a telephone system, line conductors connecting a plurality of subscribers stav tions, telephonic apparatus in a normally open bridge at each station, a relay individual to each station, the operation of the relay at any station introducing a break in the bridges of all other stations.

3. In a telephone system, line conductors connecting a plurality of subscribers stations, telephonic apparatus in a normally open bridge at each station, a relay individual thereto, an energizing circuit for each relay including normally closed contacts of the other relays, and a switch at each station for closing the normally open bridge thereat, the actuation of the switch relay thereat to isolate the apparatus at all other stations from the line conductors.

4. In a telephone system, line conductors connecting a plurality of subscribers stations, a bridge containing a normally open and a normally closed contact for each station, telephonic apparatus in each bridge, a switch at each station for closing the normally open contact thereat, and an electromagnetic device operating upon the actuation of a switch to open the'no-rmally closed contacts of all other stations;

5. In a telephone system, line conductors connecting a plurality of subscribers stations, a bridge containing a normally open and a normally closed contact for each station, telephonic apparatus in each bridge, a switch at each station for closing the normally open contact thereat, and means individual to a station operating upon the actuation of the switch thereat to open the normally closed contacts of all other stations.

6. In a telephone system, line conductors connecting a plurality of subscribers stations, a bridge containing a normally open and a normally closed contact for each station, telephonic apparatus in each bridge, a switch at each station for closing the normally open contact thereat, and an electromagneticdevice in the bridge of a station operating upon the actuation of the switch thereat to open the normally closed contacts of all other stations. I

In Witness whereof, I hereunto subscribe my namethis 12th day of May A. D., 1915.

OLOF DAVID MATTHIAS GUTHE.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents.

Washington, D. G. 

